From 04016e3bcf1463bbb5aeda1861767f37a0697843 Mon Sep 17 00:00:00 2001
From: Brooks Prumo <brooks@solana.com>
Date: Wed, 23 Nov 2022 09:11:28 -0500
Subject: [PATCH] Don't wait for EAH unless feature is enabled (#28938)

---
 runtime/src/bank.rs                 | 24 +++++++++++++++---------
 runtime/src/serde_snapshot/tests.rs |  5 +++--
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index c4eeaacc67..f7dad2e36f 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -7787,22 +7787,28 @@ impl Bank {
     /// EAH *must* be included.  This means if an EAH calculation is currently in-flight we will
     /// wait for it to complete.
     pub fn get_epoch_accounts_hash_to_serialize(&self) -> Option<EpochAccountsHash> {
-        let should_get_epoch_accounts_hash = epoch_accounts_hash::is_enabled_this_epoch(self)
+        let should_get_epoch_accounts_hash = self
+            .feature_set
+            .is_active(&feature_set::epoch_accounts_hash::id())
+            && epoch_accounts_hash::is_enabled_this_epoch(self)
             && epoch_accounts_hash::is_in_calculation_window(self);
-        let (epoch_accounts_hash, measure) = measure!(should_get_epoch_accounts_hash.then(|| {
-            self.rc
-                .accounts
-                .accounts_db
-                .epoch_accounts_hash_manager
-                .wait_get_epoch_accounts_hash()
-        }));
+        if !should_get_epoch_accounts_hash {
+            return None;
+        }
+
+        let (epoch_accounts_hash, measure) = measure!(self
+            .rc
+            .accounts
+            .accounts_db
+            .epoch_accounts_hash_manager
+            .wait_get_epoch_accounts_hash());
 
         datapoint_info!(
             "bank-get_epoch_accounts_hash_to_serialize",
             ("slot", self.slot(), i64),
             ("waiting-time-us", measure.as_us(), i64),
         );
-        epoch_accounts_hash
+        Some(epoch_accounts_hash)
     }
 
     /// Convenience fn to get the Epoch Accounts Hash
diff --git a/runtime/src/serde_snapshot/tests.rs b/runtime/src/serde_snapshot/tests.rs
index def07fcd63..7c29430ccf 100644
--- a/runtime/src/serde_snapshot/tests.rs
+++ b/runtime/src/serde_snapshot/tests.rs
@@ -8,7 +8,7 @@ use {
         append_vec::AppendVec,
         bank::{Bank, Rewrites},
         epoch_accounts_hash,
-        genesis_utils::{activate_all_features, activate_feature},
+        genesis_utils::{self, activate_all_features, activate_feature},
         snapshot_utils::ArchiveFormat,
         status_cache::StatusCache,
     },
@@ -17,7 +17,7 @@ use {
     solana_sdk::{
         account::{AccountSharedData, ReadableAccount},
         clock::Slot,
-        feature_set::disable_fee_calculator,
+        feature_set::{self, disable_fee_calculator},
         genesis_config::{create_genesis_config, ClusterType},
         pubkey::Pubkey,
         signature::{Keypair, Signer},
@@ -228,6 +228,7 @@ fn test_bank_serialize_style(
 ) {
     solana_logger::setup();
     let (mut genesis_config, _) = create_genesis_config(500);
+    genesis_utils::activate_feature(&mut genesis_config, feature_set::epoch_accounts_hash::id());
     genesis_config.epoch_schedule = EpochSchedule::custom(400, 400, false);
     let bank0 = Arc::new(Bank::new_for_tests(&genesis_config));
     let eah_start_slot = epoch_accounts_hash::calculation_start(&bank0);